Project Overview
The Christian Revival Church (CRC) seating accommodates
4 500 congregants and is enclosed with a curved structural steel roof consisting of triangular radiused roof trusses spaced 10m apart over an area of 80m x 68m. The seven unique structural steel triangular space frame ‘Toblerone” trusses are manufactured from circular hollow sections with varying spans up to 50m.
The auditorium roof structure was analysed using the Prokon frame analysis program with loading modelled in 20 different load combinations. The Toblerone trusses which span across the entire main auditorium building, are supported by reinforced concrete columns with corbels at each end of the trusses as well as by an intermediate reinforced concrete ring beam. The top chords, which under most load combinations are in compression, are braced together with horizontal circular members. The trusses are roughly 1.9m deep and 2.4m wide in plan and are curved to provide a curved roof profile and suitable slope for rainwater disposal.
The trusses have intermediate support from a ring beam which is curved in plan, forming the rear perimeter of the auditorium.
The spiral ramp is a significant architectural and structural feature in the entrance hall of the church. The ramp starts in the lower parking basement and provides safe and comfortable vertical access to all floors for all users including those in wheelchairs.
One central reinforced concrete column in the center of the spiral ramp supports a circular reinforced concrete beam and slab system at the roof. This slab and beam system is braced by perimeter columns and beams which also support the glass facade. 55mm Diameter steel hangars with adjustable couplers are hung from the slab and beam system and support the inner steel stringer channels.
The steel ring structure was added to overcome an aesthetic challenge encountered during the initial design of the concrete staircase. The design of the staircase was modified by removing the reinforced concrete columns which initially extended from the first landing to the second landing and replacing these with a circular hollow section steel ring structure.
